Method for transmitting/receiving internet-based content and transmitter/receiver using same

ABSTRACT

The present invention relates to a method for transmitting/receiving contents through a network such as the Internet, and to a transmitter/receiver using same, the transmission method comprising: converting content stored in a file format into a delivery format; and transmitting the content converted into the delivery format using an IP packet, wherein the delivery format includes indicator information for expressing whether a program clock reference (PCR) has been transmitted to the IP packet.

TECHNICAL FIELD

The present invention relates to a method and device fortransmitting/receiving various multimedia contents through the Internet.

BACKGROUND ART

Currently, digital broadcasts such as terrestrial wave, cable,satellite, or Digital Multimedia Broadcasting (DMB) stream AV contentsmostly using MPEG-2 Transport Stream (TS).

Additionally, due to the recent rapid growth of the internet, amultimedia service providing contents by using an Internet Protocol (IP)network as a main transmission network is becomes active, and digitalbroadcasts are evolving in the direction that requires a large amount oftransmission data, for example, stereo 3D video broadcast, Ultra HighDefinition (UHD) broadcast, multi-point 3D video broadcast, and hologrambroadcast.

However, the MPGE-2 TS having a 188 byte fixed length packet may beinefficient in transmitting contents having a higher resolution than atypical HDTV through the IP network.

DISCLOSURE OF THE INVENTION Technical Problem

Embodiments provide a contents delivery format having a structure ofefficient transmission in an internet environment and a content fileformat having a structure of easy mutual conversion with the deliveryformat.

Embodiments also provide an efficient conversion method between thedelivery format and a file format.

Embodiments also provide a method and device for transmitting/receivingcontents, which receive and process contents having the delivery formatand file format.

Technical Solution

In one embodiment, a method of transmitting contents through internetincludes: converting contents stored in a file format into a deliveryformat; and transmitting the contents converted into the delivery formatby using an IP packet, wherein the delivery format comprises indicatorinformation for representing whether a Program Clock Reference (PCR) istransmitted in the IP packet.

In another embodiment, a method of receiving contents through internetincludes: converting contents received in a delivery format into a fileformat; and storing the contents converted into the file format, whereinthe delivery format comprises indicator information for representingwhether a PCR is transmitted in an IP packet and a clock reference valuefor clock synchronization between transmitters/receivers, and the clockreference value is selectively received according to the indicatorinformation.

In further another embodiment, a device of transmitting contents throughinternet includes: a format conversion unit for converting contentsstored in a file format into a delivery format; and a packettransmission unit for transmitting the contents converted into thedelivery format by using an IP packet, wherein the delivery formatcomprises indicator information for representing whether a PCR istransmitted in the IP packet, and a clock reference value for clocksynchronization between transmitters/receivers is selectively includedin the delivery format according to the indicator information.

In still further another embodiment, a device of receiving contentsthrough internet includes: a format conversion unit for convertingcontents received in a delivery format into a file format; and acontents storage unit for storing the contents converted into the fileformat, wherein the delivery format comprises indicator information forrepresenting whether a PCR is transmitted in an IP packet and a clockreference value for clock synchronization betweentransmitters/receivers, and the clock reference value is selectivelyreceived according to the indicator information.

Advantageous Effects

According to an embodiment of the present invention, by selectivelyincluding a clock reference value in a delivery format of contentstransmitted from a contents transmitting device through internet, aclock between transmitters/receivers may be effectively synchronized.

Additionally, by including the delivery format into payload of an IPpacket and transmitting it, mutual conversion with a file format maybecome easy and overhead due to unnecessary information included may bereduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conceptual diagram illustrating an internet based contentstransmitting/receiving system according to an embodiment of the presentinvention

FIG. 2 is a view illustrating a data flow in a transmission/receptionsystem of FIG. 1.

FIG. 3 is a block diagram illustrating a configuration oftransmission/reception system according to an embodiment of the presentinvention.

FIG. 4 is a view illustrating a file format of contents.

FIG. 5 is a block diagram illustrating a file format of contentsaccording to a first embodiment of the present invention.

FIG. 6 is a view of syntax illustrating the architecture of the trak(PSI/SI) of FIG. 5 according to an embodiment of the present invention.

FIG. 7 is a view when an mdat for subtitle is added in the file formatof FIG. 5.

FIG. 8 is a view of syntax illustrating the architecture of supplementdata for subtitle.

FIG. 9 is a view illustrating a file format of contents according to asecond embodiment of the present invention.

FIG. 10 is a view of syntax illustrating the architecture of the mdat(PSI/SI) of FIG. 9 according to an embodiment of the present invention.

FIG. 11 is a view illustrating a delivery format of contents accordingto an embodiment of the present invention.

FIGS. 12 and 13 are views illustrating a method of converting a fileformat of contents into a delivery format.

FIG. 14 is a block diagram illustrating a configuration of a contentstransmitting device according to a first embodiment of the presentinvention.

FIGS. 15 and 16 are views illustrating a method of converting a fileformat of contents into a delivery format according to a firstembodiment of the present invention.

FIG. 17 is a block diagram illustrating a configuration of a contentstransmitting device according to a second embodiment of the presentinvention.

FIGS. 18 and 19 are views illustrating a method of converting a deliveryformat of contents into a file format according to a first embodiment ofthe present invention.

FIG. 20 is a block diagram illustrating a configuration of a contentsreceiving device according to a first embodiment of the presentinvention.

FIGS. 21 and 22 are views illustrating a method of converting a deliveryformat of contents into a file format according to a second embodimentof the present invention.

FIG. 23 is a block diagram illustrating a configuration of a contentsreceiving device according to a second embodiment of the presentinvention.

FIG. 24 is a block diagram illustrating a configuration of an IPTVreceiver according to a first embodiment of the present invention.

FIG. 25 is a block diagram illustrating a configuration of an IPTVreceiver according to a second embodiment of the present invention.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, method and device for transmitting/receiving contents willbe described in more detail according to an embodiment of the presentinvention with reference to FIGS. 1 to 25.

Hereinafter, detailed descriptions related to well-known functions orconfigurations will be ruled out in order not to unnecessarily obscuresubject matters of the present invention. Then, terms described laterare defined in consideration of the functions of the present invention,but may vary according to the intention or convention of a user oroperator. Therefore, its definition will be made based on the overallcontents of this specification.

FIG. 1 is a conceptual diagram illustrating an internet based contentstransmitting/receiving system according to an embodiment of the presentinvention.

Referring to FIG. 1, a broadcasting station 20 receives contents from acontent provider 10 and stores them in a media DataBase (DB). Forexample, the contents provided from the content provider 10 may havedifferent formats (original format) according to the types ofcorresponding contents or content providers providing them, and thebroadcasting station 20 may convert the formats of the contents providedfrom the content provider 10 into a file format, a format to be easilystored, and then, may store them in the media DB.

Moreover, the broadcasting station 20 converts the contents of the fileformat stored in the media DB into a delivery format, a format to beeasily transmitted, and then, transmits them through a network such asinternet.

Additionally, a receiver 30 receives or plays the contents of a deliveryformat transmitted from the broadcasting station 20, or converts thedelivery format in order to store it in a local storage.

In this case, the broadcasting station 20 may store the contentsprovided from the content provider 10 in the media DB with an originalformat or streaming format (for example, MPEG2 TS).

However, in relation to the contents of the original format, it may takea lot of time to convert them into a streaming format for transmission,and in relation to the streaming format, unnecessary information may beincluded so that DB storage capacity needs to be increased to store it.

Moreover, the format of the contents stored in the receiver 30 may varyaccording to a corresponding receiver or a local storage equippedtherein, so that the contents may not be used in various devices.

According to an embodiment of the present invention, the internet basedcontents transmitting/receiving system reduces overhead according tounnecessary information included and provides a delivery format and fileformat easy for mutual conversion.

The delivery format may have an advantageous structure in an environmentwhere transmission is easy via a network such as internet, for example,there are relatively large errors, and may be designated as a wireformat.

Moreover, the delivery format is designed for easy transmission ofcontents through a network such as internet, but is not limited thereto,and thus may be used for storing the contents.

Additionally, the file format may have an advantageous structure in anenvironment where contents are be easily stored in a local DB or storagemedium, for example, there are relatively small errors, and may bedesignated as a wireless format.

The file format is designed to be easily store contents, but is notlimited to being used for the storage of the contents, and thus may beused for contents transmission.

FIG. 2 is a view illustrating a data flow in a transmission/receptionsystem of FIG. 1. The data flow is shown in terms of protocol stack.

The protocol stack is core software implementing a correspondingcommunication protocol when communication is provided between eachdevice, as a group of software modules implementing communicationprotocols necessary when different devices data-communicate with eachother. A profile prescribes a communication protocol used in anapplication in order to obtain interconnectivity.

Referring to FIG. 2, when the broadcasting station 20 transmits contentsthrough internet, a transfer protocol may be changed as the transmittedcontents pass through a router 25. For example, the contents may betransmitted from the broadcasting station 20 to the router 25 in aReal-time Transport Protocol (RTP) and from the rougher 25 to thereceiver 30 in a HyperText Transfer Protocol (HTTP).

However, when seen from a media delivery layer, the contents aretransmitted in a regardless of a protocol used in a consistent transferformat regardless of a protocol used in the router 25, and thus, interms of a transceiver device, the burden of a transmission terminal maybe reduced.

Accordingly, the delivery format according to an embodiment of thepresent invention is designed to have protocol-transparentcharacteristics, as mentioned above, and the file format may be designedto have the protocol-transparent characteristics in order for easyconversion of the delivery format.

Referring to FIGS. 1 and 2, the broadcasting station 20 may be oneexample representing a function of a contents transmitting deviceaccording to an embodiment of the present invention, and the receiver 30may be one example representing a function of a contents receivingdevice according to an embodiment of the present invention.

Moreover, the service provider 10 and the broadcasting station 20 areseparated in FIG. 1, but different from that, may be integrated into oneto provide contents to the receiver 30 through internet.

FIG. 3 is a block diagram illustrating a simple configuration of atransceiver system according to an embodiment of the present invention.

Referring to FIG. 3, the architecture of a media transmission system fortransmitting/receiving contents through a network such as internet mayinclude an encapsulation layer 31, a transport layer 32, and a controllayer 33.

The encapsulation layer 31 may generate data corresponding to contentsthat a service provider is to provide and information thereon by usingassets including a video, an image, an audio, web contents, orapplication.

For example, the encapsulation layer 31 may encapsulate theabove-mentioned one or more of assets and information thereon as an itemfor transmission, and then, may deliver it to the transport layer 32.

Moreover, the transport layer 32 may transmit the item delivered fromthe encapsulation layer 31 and the data delivered from the control layer33.

Additionally, the control layer 33 may control an operation of theencapsulation layer 31 and the control layer 33 in order to transmit theassets and item.

In the encapsulation layer 31 described with reference to FIG. 3, theassets including a video, an image, an audio, web contents, orapplication may have a file format according to an embodiment of thepresent invention, and the item encapsulated for transmission may have adelivery format according to an embodiment of the present invention.

Hereinafter, referring to FIGS. 4 to 10, the configuration of a contentsfile format according to an embodiment of the present invention will bedescribed in detail.

FIG. 4 is a view illustrating a file format of contents, i.e. an ISO/IEC14496-12 ISO Base Media file format.

Referring to FIG. 4, a file format 100 used for storing contents mayinclude a ftyp) box 101 for storing type information on a file, an mdatbox 120 for storing audio data and video data, and a moon box 110 forstoring detail information for playing audio data and video data.

In more detail, a trak(audio) 111 included in the move box 110 mayinclude metadata representing information on the audio data (that is,data stored in the mdat(audio) 121) included in the mdat box 120.

Additionally, a trak(video) 112 included in the move box 112 may includemetadata representing information on the video data (that is, datastored in the mdat(video) 122) included in the mdat box 120.

For example, the trak(audio) 111 and the trak(video) 112 may representunique information on corresponding mdat such as codec, the position andsize of data, or data sample size and position, with respect to the datastored in each corresponding mdat.

Moreover, the audio data and the video data included in the mdat box 120may be data obtained using various compression methods, and for example,the video data stored in the mdat(video) 122 may be data compressedaccording to the methods such as MPEG-2 Video, H.26x, VC1, Motion JPEG,MPEG-4 Visual, MPEG-4 Part 10 Advanced Video Coding(or H.264), or MPEG-4Scalable Video Coding.

The file format according to an embodiment of the present invention maybe configured to have a compatibility with the above-mentioned ISO/IEC14496-12 ISO Base Media file format, and may include compositioninformation on a program configured using the data stored in the mdatbox 120, in the moove box 110 or the mdat box 120.

The program composition information represents how to constitute datasuch as audio or video in a corresponding program, and hereinafter, willbe designated as ‘PSI/SI information’.

The PSI/SI information may include Program Specific Information (PSI)and Service Information (SI) on a corresponding program.

For example, the PSI refers to information that a receiver demultiplexesa specific stream in a multiplexed stream and decodes it, and the SIrefers to guide information on a service and an individual program to beprovided to a user in addition to the PSI.

In more detail, the PSI may include a Program Association Table (PAT), aProgram Map Table (PMT) or a Conditional Access Table (CAT), and the SImay include a Service Description Table (SDT), a Network InformationTable (NIT), an Event Information Table (EIT), or a Time Offset Table(TOT).

However, PSI/SI information according to an embodiment of the presentinvention is not limited to the above PSI/SI, and thus, may includevarious information necessary for constituting and playing a specificprogram by using audio or video data.

FIG. 5 is a view illustrating a contents file format according to afirst embodiment of the present invention, and description for thecomponents in the file format of FIG. 5 identical to those describedwith reference to FIG. 4 will be omitted hereinafter.

Referring to FIG. 5, in relation to the file format according to anembodiment of the present invention, a trak(PSI/SI) 115 representingPSI/SI information on a program constituted using the audio and videodata stored in the mdat box 120 may be included in the moov box 110.

For example, the trak(PSI/SI) 115 may include identificationinformation, type information, priority information, information on aconfiguration change during playback, and supplement information, withrespect to each of at least one mdat constituting a correspondingprogram.

Moreover, when the file format includes a plurality of programs, thetrak(PSI/SI) 115 may be in plurality in correspondence to each of theprograms.

In this case, the moov box 110 may include a trak(audio) 111 and atrak(video) 112 in order to represent unique information on each of themdat(audio) 121 and the mdat(video) 122.

Or, unique information such as codec on audio data and video dataincluded in the trak(audio) 111 and the trak(video) 112 may be signaledfrom the trak(PSI/SI)(115) as supplement information.

As mentioned above, since the trak(PSI/SI)(115) signals PSI/SIinformation on a program and audio and video related informationsimultaneously, the conversion from the file format to a delivery formatmay become easy.

Hereinafter, referring to FIG. 6, the configuration of the trak (PSI/SI)will be described according to an embodiment of the present invention.

Referring to the syntax shown in FIG. 6, the trak (PSI/SI) may include aprogram_number field, a number_of_mdat field, an mdat_id field, anmdat_type field, a priority field, a start_time field, a duration field,a supplement_length field, and a supplement_data field.

The program_number field may represent program identificationinformation, for example, an unique number, which signals PSI/SIinformation by the trak (PSI/SI).

For example, if there are a plurality of programs in the file formathaving the structure shown in FIG. 5, trak(PSI/SI) as much as the numberof programs may be included in the moon box, and the programs may bedistinguished from each other by using a value of the program_numberfield.

Moreover, as mentioned above, the file format according to an embodimentof the present invention was described with the example usingprogram_number in order to identify a program, but besides the programnumber, various formats of an identifier may be assigned to eachprogram.

The number_of_mdat field may represent the number of mdats constitutinga corresponding program. For example, when the program includes anmdat(audio) having audio data and an mdat(video) having video data, thenumber_of_mdat field may have the value of ‘2’.

Moreover, the mdat_id field may represent the unique id of acorresponding mdat as an identifier for identifying the mdatconstituting a corresponding program.

The mdat_type field represents a type of an mdat constituting acorresponding program, and for example, according to the type of data inthe mdat, ‘1’ represents video, ‘2’ represents audio, and ‘0’ is areserved value for another type.

The priority field represents a priority of a corresponding mdat, andmay be a flag that represents whether data in a corresponding mdat areplayed by default.

Moreover, the priority field may designate one main mdat to each type ofthe mdat. Also, a value of the priority field may be set, for example,the main mdat of each type is set to ‘0’ and a sub mdat is set to ‘1’.

For example, when there are two mats corresponding to an audio typeamong the mdats constituting a corresponding program, among the twoaudio type mdats, an mdat having the priority field value of ‘0’ isplayed by default during playback of the program, and an mdat having thepriority field value of ‘1’ is selectively played according to a user'sselection or a specific playback environment.

Moreover, if there is only one mdat corresponding to a specific mdattype among mdats constituting a corresponding program, the priorityfield to the mdat has the value of ‘0’.

Moreover, a section that a corresponding mdat is used may be designatedby the start_time field and the duration field.

The start_time field represents the start time of a section that acorresponding mdat is used, and for example, when a corresponding mdatis used from the beginning of the program, the start_time field may havethe value of ‘0’.

The duration field represents the length of a section that acorresponding mdat is used, and when it has the value of ‘0xFF’, itindicates that the corresponding mdat does not change and is usedthroughout the entire program.

Moreover, values of the start_time field and the duration field may beset by a msec unit, but are not limited thereto, and for example, when abitrate of data included in a corresponding mdat is set, the values maybe designated using a frame number.

The above start_time field and duration field is used as configurationchange information (that is, information on an item that a programconfiguration is changed during its playback, and this may representtime information on an mdat added or changed during program playbackwhen multi-audio or multi-view is supported or an audio/video mdatconstituting a program is changed.

For example, from the start of a program that PSI/SI information issignaled by the trak (PSI/SI), an audio type main mdat changes from themdat of ‘id1’ into the mdat of ‘id2’ at the time after 180 msec, andwhen the mdat of ‘id2’ is used for 130 msec, the start_time field valueis set to ‘0’ and the duration field value is set to ‘180’ with respectto the mdat of ‘id1’, and the start_time field value is set to ‘180’ andthe duration field value is set to ‘130’ with respect to the mdat of‘id2’.

Additionally, as mentioned above, as a configuration changes duringprogram playback, when the file format shown in FIG. 5 is converted intoa delivery format, the version of PSI/SI signaling information may beupdated according to the start_time field value and the duration fieldvalue.

Moreover, the start_time field and the duration field are just oneembodiment representing configuration change information on a program,and the present invention is not limited thereto. The configurationchange information may be expressed in various formats in order torepresent a section that an mdat is used on the time axis.

For example, the duration field may be replaced with an end_time fieldthat represents a time at which a usage of a corresponding mdat ends,and in this case, the duration field value may be calculated by adifference between the end_time field value and the start_time fieldvalue.

The supplement_length field may designate the length of supplementinformation when there is the supplement information on a correspondingmdat.

Additionally, the supplement_data field represents supplementinformation on a corresponding mdat, and for example, as described withreference to FIG. 5, when the trak (PSI/SI) includes unique informationsuch as codec on audio/video data included in an mdat(audio) and anmdat(video), the unique information on the audio/video data may beincluded in the supplement_data field.

Referring to FIG. 7, the mdat box 120 of the file format 100 may furtherinclude an mdat(subtitle) 123 for storing subtitle data.

Furthermore, PSI/SI information related to the mdat(subtitle) 123 may besignaled by the trak (PSI/SI) having the configuration described withreference to FIG. 6, and in this case, the mdat_type field value to themdat(subtitle) 123 may be designated to ‘3’.

Since a method of signaling PSI/SI information related to themdat(subtitle) 123 by using the trak (PSI/SI) may be identical to thatdescribed with reference to FIG. 6, its detailed description will beomitted.

The supplement_data field of the trak (PSI/SI) may include uniqueinformation on subtitle data in the mdat(subtitle) 123, for example,language in use, a subtitle type, and configuration page information, assupplement information.

FIG. 8 is a view illustrating the configuration of supplement data for asubtitle in syntax according to an embodiment of the present invention,and when the mdat_type field value is ‘3’ in the trak (PSI/SI) shown inFIG. 6 is ‘3’, it represents the subtitle related supplement informationdesignated by the supplement_data field.

Referring to FIG. 8, since the supplement_data field including subtitlerelated supplement information uses total 8 bytes, the supplement_datafield value may be designated to ‘8’.

An ISO_639_language_code field represents a language used in a subtitle,and for this, may have a language code defined in ISO 639-2, as a fieldvalue. For example, when ISO_639_language_code field value is ‘kor’, thelanguage used in a subtitle is Korean language, and when it is ‘eng’,the language used in a subtitle is English.

Moreover, a subtitling_type field represents a subtitle type, and forexample, a field value of ‘0’ may represent a general type, ‘1’ mayrepresent a Vertical Blanking Interval (VBI) type, and ‘2’ may representa type for the hearing impaired.

An aspect_ratio field represents that a subtitle is configured to be fitfor what format of a display. That is, when the field value is ‘1’, acorresponding subtitle is configured to fit for a display having a 4:3aspect ratio display, when the field value is ‘2’, a correspondingsubtitle is configured to fit for a display having a 16:9 aspect ratiodisplay, and when the field value is ‘3’, a corresponding subtitle isconfigured to fit for a display having a 2.35:1 aspect ratio display.That is, when the field value is ‘0’, a corresponding subtitle isconfigured regardless of a display.

Additionally, a composition_page_id field represents an id foridentifying each page constituting a corresponding subtitle, and anancillary_page_id field represents an id for indentifying an auxiliarypate among pages constituting a corresponding subtitle.

As described with reference to FIGS. 7 and 8, according to a structureof an mdat(subtitle), it is possible to use an existing subtitle streamas it is.

FIG. 9 is a view illustrating a contents file format according to asecond embodiment of the present invention, and description for thecomponents in the file format of FIG. 9 identical to those describedwith reference to FIGS. 4 to 8 will be omitted hereinafter.

Referring to FIG. 9, in relation to the file format according to asecond embodiment of the present invention, an mdat(PSI/SI) 125 forstoring PSI/Si related data on a program may be included in an mdat box120.

That is, in the case of the file format according to the firstembodiment of the present invention as described with reference to FIGS.5 to 8, PSI/SI information on a program is included in the trak(PSI/SI)115 in the moon box 110, but in the case of the file format according tothe second embodiment of the present invention, the PSI/SI informationmay be included in the mdat(PSI/SI) 125 in the mdat box 120.

Since the configuration of the PSI/SI information in the mdat(PSI/SI)125 is similar to the configuration of the PSI/SI information includedin the trak(PSI/SI) 115 as described with reference to FIGS. 5 to 8,hereinafter, only a different component from the task(PSI/SI) 115 amongthe configuration of the mdat(PSI/SI) 125 will be mainly described.

The mdat(PSI/SI) 125 may include identification information on each ofat least one mdat constituting a corresponding program, typeinformation, priority information, and supplement information, inaddition to identification information and version information on PSI/SIinformation, with respect to a program included in the file format 100.

Moreover, when the file format 100 includes a plurality of programs, onemdat(PSI/SI) 125 may include all PSI/SI information on the plurality ofprograms.

By including PSI/SI information on at least one program in the fileformat 100 in the mdat(PSI/SI) 125, the size of PSI/SI related datastored in the mdat box 120 may be increased, but conversion to adelivery format may become easier.

Additionally, the moon box 110 includes the trak(audio) 111 and thetrak(video) 112 in order to represent unique information on each of themdat(audio) 121 and the mdat(video) 122.

Or, unique information such as codec on audio data and video dataincluded in the trak(audio) 111 and the trak(video) 112 may be signaledfrom the mdat(PSI/SI) 125 as supplement information.

As mentioned above, since the mdat(PSI/SI) 125 signals PSI/SIinformation on a program and audio and video related informationsimultaneously, the conversion from the file format to a delivery formatmay become easy.

Hereinafter, referring to FIG. 10, the configuration of the mdat(PSI/SI) will be described according to an embodiment of the presentinvention.

Referring to the syntax shown in FIG. 10, the mdat(PSI/SI) may include aPSI/SI_info_id field, a version field, a number_of_programs field, aprogram_number field, a number_of_mdat field, an mdat_id field, anmdat_type field, a priority field, a supplement_length field, and asupplement_data field.

The PSI/SI_info_id field represents an id for identifying the type ofcorresponding PSI/SI information, and for example, information acorresponding Program Map Table (PMT) and Program Association Table(PAT) defined in MPEG-2 TS may have the field value of ‘0’.

Moreover, when PSI/SI information necessary besides the PMT and PAT isadditionally configured, an id for identifying the type of correspondingPSI/SI information is numbered, and then, is added as the PSI/SI_info_idfield value.

The version field value is updated when corresponding PSI/SI informationis changed. For example, when the number of mdats constituting acorresponding program is increased or reduced or the configuration of anentire program is changed during program playback, the version fieldvalue may be updated.

Additionally, when the program composition information is changed, theversion information is updated and a changed content of the programcomposition information may be reflected on the mdat(PSI/SI) in realtime simultaneously.

In this case, since the changed content of the PSI/SI information isalready reflected on the mdat(PSI/SI), like the file format according tothe first embodiment of the present invention as described withreference to FIGS. 5 to 8, usage section information on each mdat doesnot need to be represented additionally by using the start_time fieldand the duration field.

Moreover, the number_of_programs field may represent the number ofprograms in the file format 100, and the program_number field mayrepresent an unique number for identifying each program.

For example, if there are a plurality of programs in the file format 100having the structure shown in FIG. 9, there are loops as much as thenumber of the programs in the mdat(PSI/SI), and the programs may beseparated from each other by using the program_number field value.

The number_of_mdat field may represent the number of mdats constitutinga corresponding program, and the mdat_id field may represent an uniqueid for identifying an mdat constituting a corresponding program.

Moreover, the mdat_type field may represent the type of an mdatconstituting a corresponding program, and the priority field mayrepresent the priority of a corresponding mdat.

Furthermore, the supplement_length field may designate the length ofsupplement information when there is the supplement information on acorresponding mdat, and the supplement_data field may representsupplement information on a corresponding mdat.

For example, the supplement_data field of the mdat (PSI/SI) may includeunique information on subtitle data in the mdat(subtitle) 123, forexample, language in use, a subtitle type, and configuration pageinformation, as supplement information.

Hereinafter, referring to FIG. 11, the configuration of a contentsdelivery format according to an embodiment of the present invention willbe described in detail.

Referring to FIG. 11, when contents are transmitted through internet,since the delivery format in an IP packet, additional address andfragmentation therefore may not be necessary.

Moreover, since the IP packet has a variable length, a delivery formataccording to an embodiment of the present invention may be configured tosupport the variable length.

For example, mdats included in the file format 100 described withreference to FIGS. 4 to 10 are cut according to a time window having apredetermined size, and is converted into a delivery format, and theconverted delivery format is included in an IP packet, and then, issequentially transmitted.

Referring to the syntax shown in FIG. 11, the delivery format may beconfigured including an mdat_id field, a clock_reference_indicatorfield, a data_length field, a PCR_base/PCR_extension field, anumber_of_mdat field, an mdat_id field, an mdat_type field, a priorityfield, and a payload_data_byte field.

The mdat_id field may represent an unique id for identifying an mdatincluded in a delivery format, and the configuration of an id designatedby the mdat_id field value may be signaled by the PSI/SI informationdescribed with reference to FIGS. 5 to 10.

That is, the mdat_id field may designate an unique id for identifying anmdat included in the delivery format according to the unique id that thePSI/SI information in the file format 100 assigns to each mdat. Thisfunctions similar to the PID(Packet ID) defined in MPEG2 TS.

Moreover, when the PSI/SI information is included in a delivery format,the mdat_id field of a corresponding delivery format may have a valueseparately designated with refer to the PSI/SI information, for example,‘0’.

The clock_reference_indicator field may represent whether a ProgramClock Reference (PCR) is transmitted to an IP packet including acorresponding delivery format, and the PCR_base/PCR_extension field mayrepresent a clock reference value.

For example, when the clock_reference_indicator field value is ‘1’, thePCR is transmitted through a corresponding IP packet, and thetransmitted PCR may have a clock reference value designated by thePCR_base/PCR_extension field.

On the contrary, when the clock_reference_indicator field value is ‘0’,it is represented that the PCR is not transmitted through acorresponding IP packet.

The PCR is a value that is included in a delivery format in order to setthe STC at the reception side to an intended value at the transmissionside, as a total 42 bit time reference value for setting or compensatingfor a value of System Time Clock (STC).

The total 42 bit PCR is divided into a 33 bit PCR_base area and a 9 bitPCR_extension area. The PCR_base may use 1/300 of a system clockfrequency (for example, 90 kHz) as a unit and the PCR_extension may usea system clock frequency (for example, 27 kHz) as a unit.

For example, when the clock_reference_indicator field value of adelivery format in an IP packet received from the transmission side is‘1’, the reception side may calculate the PCR according to the PCR_basefield value and the PCR_extension field value through the followingEquation 1.

Equation 1

PCR=PCR_base×300+PCR_extension

Moreover, the data_length field may represent the length of dataincluded in a corresponding data unit.

The payload_data_byte field is an area where actual data stored in eachmdat are transmitted, and for example, each of audio, video, subtitledata corresponding to mdats 121, 122, 123, and 125 cut according to thetime window, or PSI/SI related data may be transmitted by a byte unitthrough the payload_data_byte field.

Additionally, the PSI/SI information stored in the trak(PSI/SI) 115 maybe transmitted at each predetermined period through thepayload_data_byte field.

The delivery format described with reference to FIG. 11 may be includedthe payload of an IP packet according to a protocol such as UserDatagram Protocol (UDP), Transmission Control Protocol (TCP), RTP orHTTP, and accordingly, since an additional parameter for transmission isnot required, overhead unnecessary for transmitting contents throughinternet may be reduced.

Moreover, the configuration of the PSI/SI information transmitted usingthe above-mentioned delivery format may be identical to that of themdat(PSI/SI) among the file formats according to the second embodimentof the present invention as described with reference to FIG. 10.

Accordingly, a configuration of PSI/SI information transmitted in adelivery format according to an embodiment of the present invention willbe briefly described with reference to FIG. 10.

Referring to FIG. 10 again, the PSI/SI_info_id field of the PSI/SIinformation included in a delivery format may represent an id foridentifying the type of corresponding PSI/SI information, and a versionfield value may be updated when corresponding PSI/SI information ischanged.

For example, when the number of mdats constituting a program isincreased or reduced while contents are transmitted through an IPnetwork or the configuration of an entire program is changed, theversion field value may be updated.

However, since a change of the PSI/SI information in the delivery formatis signaled in real time, like the file format according to the firstembodiment of the present invention as described with reference to FIGS.5 to 8, usage section information on each mdat does not need to berepresented additionally by using the start_time field and the durationfield.

The number_of_programs field of the PSI/SI information in the deliveryformat may represent the number of programs transmitted to acorresponding delivery format, and the program_number field mayrepresent an unique number for identifying each program.

Moreover, the number_of_mdat field may represent the number of mdatsconstituting a corresponding program, and the mdat_id field mayrepresent an unique id for identifying an mdat constituting acorresponding program.

Additionally, the mdat_type field of the PSI/SI information in thedelivery format may represent the type of an mdat constituting acorresponding program, and the priority field may represent the priorityof a corresponding mdat.

Furthermore, the supplement_length field may designate the length ofsupplement information when there is the supplement information on acorresponding mdat, and the supplement_data field may representsupplement information on a corresponding mdat.

The PSI/SI information included in a delivery format and transmitted mayinclude composition information on stream, which is currently intransmission by using an IP packet, and also since the PSI/SIinformation has a configuration compatible with that of the file format100 as described with reference to FIGS. 4 to 10, mutual conversion maybe easy.

A contents transmitting method according to an embodiment of the presentinvention includes converting contents stored in a file format into adelivery format; and transmitting the contents converted into thedelivery format by using an IP packet.

Additionally, a contents receiving method according to an embodiment ofthe present invention includes converting contents received in adelivery format into a file format; and storing the contents convertedinto the file format.

Moreover, in the contents transmitting/receiving method, the file formatmay have the structure described with referent to FIGS. 4 to 10, and thetransmission format may have the structure described with reference toFIG. 12.

Hereinafter, referring to FIGS. 12 to 23, a conversion method between afile format and a delivery format according to an embodiment of thepresent invention and configurations of a transmission device and areception device using the same will be described.

FIGS. 12 and 13 are views illustrating a method of converting a fileformat into a delivery format, and that is, a method of convertingcontents stored in a file format according to the first embodiment ofthe present invention as described with reference to FIGS. 5 to 8 into adelivery format according to an embodiment of the present invention asdescribed with reference to FIG. 11 will be described.

Referring to FIG. 12, when contents are stored in a server of a serviceprovider with the above-mentioned file format 100, the service providerconverts the contents stored in the file format 100 into the deliveryformat 200 in order to transmit the contents.

In this case, the PSI/SI information of the trak(PSI/SI) 115 included inthe moon box 110 of the file format 100 may be converted into the PSI/SIsignaling information 210, and may be transmitted at each predeterminedperiod.

Moreover, since the configuration of the PSI/SI signaling information210 in the delivery format 200 is identical to that described withreference to FIG. 10, its detailed description will be omitted.

In the PSI/SI information stored in the trak(PSI/SI) 115, according tothe configuration change information of the start time/duration fielddescribed with reference to FIG. 6, after its version is updated and itschanged contents are reflected, the PSI/SI information may betransmitted.

That is, the transmission device (for example, a service providerserver) determines whether the PSI/SI information is changed accordingto the start time/duration field values, and when the PSI/SI informationis changed, the changed PSI/SI information is reflected on the PSI/SIsignaling information 210 in order to update a version.

Accordingly, even through the reception device (for example, an IPTVreceiver) accesses the service provider service at some point, effectivePSI/SI information may be received at the current access time.

Moreover, each of an mdat(audio), an mdat(video), and an mdat(subtitle)stored in the file format 100 is cut according to the time window Whaving a predetermined size, and thus, an audio packet stream 221, avideo packet stream 222, and a subtitle packet stream 223 may besequentially transmitted.

For example, the each mdat is converted into a packet streamtransmittable using internet, and the converted packet stream may beidentified by the mdat_id field described with reference to FIG. 11.

Additionally, in the case of a corresponding IP packet including PCR,for example, when the clock_reference_indicator field value is ‘1’ inthe delivery format 200 as described with reference to FIG. 11, theclock reference value Clock Ref. 231 of the transmission device isinserted into the delivery format 200 and is transmitted.

Each of the PSI/SI signaling information 210, the audio packet stream221, the video packet stream 222, and the subtitle packet stream 223 maybe included in the payload of an IP packet transmitted from the serviceprovider, and for example, they may be included by a byte unit in thepayload_data_byte field of the delivery format 200 as described withreference to FIG. 11.

As described with reference to FIG. 12, by converting the trak(PSI/SI)of the file format 100 into a packet on the basis of the compatibilityof PSI/SI information and transmitting the packet, the contents storedin the file format 100 may be easily converted into the delivery format2000 of an IP packet unit.

FIG. 13 is a flowchart illustrating a method of converting a file formatinto a delivery format according to an embodiment of the presentinvention. FIG. 14 is a block diagram illustrating a configuration of acontents transmitting device according to a first embodiment of thepresent invention. Hereinafter, the conversion method of FIG. 13 will bedescribed in more detail in linkage with the block diagram shown in FIG.14.

First, when the configuration of the transmission device shown in FIG.14 is briefly described, the transmission device 400 may include acontents DB 410, a moov decoder 420, a trak(PSI/SI) extraction unit 421,a PSI/SI generation unit 422, an mdat loader 430, a system clock 440, aclock reference generation unit 450, a scheduler 460, a Delivery headerinsertion unit 470, a Protocol encapsulation unit 480, and an Internetfrontend 490.

Additionally, a contents transmitting device according to an embodimentof the present invention includes a format conversion unit forconverting contents stored in a file format into a delivery format; anda packet transmission unit for transmitting the contents converted intothe delivery format by using an IP packet.

In this case, the format conversion unit of the contents transmittingdevice according to an embodiment of the present invention may includethe moov decoder 420, the trak(PSI/SI) extraction unit 421, the PSI/SIgeneration unit 422, the mdat loader 430, and the scheduler 460, shownin FIG. 14, and the packet transmission unit may include the deliveryheader insertion unit 470, the protocol encapsulation unit 480, and theinternet frontend 490

Referring to FIGS. 13 and 14, the transmission device 400 extractsPSI/SI information from the trak(PSI/SI) of the moov box in the storedfile format 100 of contents to be transmitted in operation S300.

The contents DB 410 of the transmission device 400 are stored andmanaged in the file format 100 described with reference to FIGS. 1 to10, and the moov decoder 420 may extract data of the moov box 110 fromthe file format 100 stored in the contents DB 410.

Moreover, the trak(PSI/SI) extraction unit 421 may extract trak(PSI/SI)data including program composition information among moov data outputtedfrom the moov decoder 420.

The PSI/SI generation unit 422 may generate the PSI/SI information ofthe delivery format 200 for streaming by using the extractedtrak(PSI/SI) data, and may output the generated PSI/SI information tothe schedule 460 in order for repeated transmission at a predeterminedperiod according to a clock provided from the system clock 440.

The mdat loader 430 may load actual contents data included in each of anmdat(audio), an mdat(video), and an mdat(subtitle), that is, audio,video, and subtitle data, and then, may deliver them to the schedule460.

Then, the transmission device 400 sets up a time window in operationS310, and determines a transmission time of the PSI/SI information inoperation S320.

The scheduler 460 of the transmission device 400 may sequentially streamthe PSI/SI information inputted from the PSI/SI generation unit 422 andthe audio, video, and subtitle data inputted from the mdat loader 430according to a system clock.

For example, the audio, video, and subtitle data inputted from the mdatloader 430 are cut according to a time window W having a predeterminedsize, and then, are sequentially transmitted. The time window W may beset by the scheduler 460.

Additionally, the scheduler 460 may determine whether it is a time totransmit the current PSI/SI information inputted from the PSI/SIgeneration unit 422 on the basis of a transmission period of the PSI/SIinformation.

When it is a time to transmit the current PSI/SI information, thetransmission device 400 confirms whether the PSI/SI information to betransmitted is updated in operation S330, and updates the version of thePSI/SI information in operation S340.

For example, the PSI/SI generation unit 422 may reflect thecorresponding changed contents on the PSI/SI signaling information 210to be included in the delivery format 200 according to a changed time ofthe PSI/SI information, and may update the version of the PSI/SIsignaling information 210.

In more detail, the PSI/SI generation unit 422 may determine whether thePSI/SI information is changed according to the program configurationchange information included in the PSI/SI information of the file format100, and if the PSI/SI information is changed, may update the version ofthe PSI/SI information to be included in the delivery format 200.

Then, the transmission device 400 converts the PSI/SI information into adelivery format in operation S350, and transmits the contents convertedinto the delivery format through a network such as internet in operationS370.

Moreover, if it is not a time to transmit the current PSI/SIinformation, the transmission device 400 converts audio/video/subtitlemdat into a delivery format according to the set up time window inoperation S360, and then, transmits the contents converted into thedelivery format through a network such as internet in operation S370.

For example, the scheduler 460 may cut the audio, video, and subtitledata inputted from the mdat loader 430 according to the time window setup in operation S310, and may include them in the delivery format 200 asdescribed with reference to FIGS. 11 and 23 in order for sequentialoutput.

The delivery header insertion unit may generate header information andmay insert it in the delivery format 200, and the protocol encapsulationunit 480 may encapsulate the delivery format 200 according to a deliveryprotocol, and then, may output it.

The delivery protocol may include various kinds of protocols such asUDP, TCP, RTP and HTTP used for data transmission through internet.

The internet frontend 490 may transmit corresponding contents throughinternet by performing physical encoding for internet transmission onthe encapsulated delivery format 200.

Moreover, the system clock 440 may provide a basic clock for streamingin the transmission device 400, and also the PSI/SI generation unit 422,the clock reference generation unit 450, and the scheduler 460 mayperform operations for contents transmission according to the systemclock.

The clock reference generation unit 450 may generate a clock referencevalue Clock Ref. for synchronization with a reception device by usingthe clock provided from the system clock 440.

The generated clock reference value Clock Ref. may be selectivelyinserted into the delivery format 200 as described with reference toFIG. 12.

Moreover, the transmission device 400 may transmit correspondingcontents by repeatedly performing operation S300 to S370 shown in FIG.12 until all mdats constituting contents are transmitted.

FIGS. 15 and 16 are views illustrating a method of converting a fileformat into a delivery format, and that is, a method of convertingcontents stored in a file format according to the second embodiment ofthe present invention as described with reference to FIGS. 9 to 10 intoa delivery format according to an embodiment of the present invention asdescribed with reference to FIG. 11 will be described. Moreover,detailed description for the same contents described with reference toFIGS. 12 and 13 in another embodiment of the conversion method will beomitted hereinafter.

Referring to FIG. 15, when contents are stored in a server of a serviceprovider in the file format 100 as shown in FIG. 9, the PSI/SIinformation of the mdat(PSI/SI) 125 may be converted into the PSI/SIsignaling information 210, and then, may be transmitted at eachpredetermined period.

Here, since the changed contents of the PSI/SI information are alreadyreflected on the mdat(PSI/SI) 125, the information included in themdat(PSI/SI) of the file format 100 may be converted into the PSI/SIsignaling information 210 of the delivery format 200 as it is, and thenmay be transmitted.

Moreover, each of an mdat(audio), an mdat(video), and an mdat(subtitle)stored in the file format 100 may be cut according to the time window Whaving a predetermined size, and thus, PSI/SI signaling information 210,an audio packet stream 221, a video packet stream 222, and a subtitlepacket stream 223 may be sequentially transmitted.

The clock reference value Clock Ref. 231 of the transmission device maybe selectively inserted into the delivery format 200 and then may betransmitted.

FIG. 16 is a flowchart illustrating a method of converting a file formatinto a delivery format according to an embodiment of the presentinvention. FIG. 17 is a block diagram illustrating a configuration of acontents transmitting device according to a second embodiment of thepresent invention. Hereinafter, the conversion method of FIG. 16 will bedescribed in more detail in linkage with the block diagram shown in FIG.17. Moreover, detailed description for the same components describedwith reference to FIG. 13 in the configuration of the transmissiondevice 400 shown in FIG. 17 will be omitted hereinafter.

Moreover, the format conversion unit of the contents transmitting deviceaccording to another embodiment of the present invention may include amoon decoder 420, an mdat loader(PSI/SI) 425, an mdat loader(A/V/Sub)430, and a scheduler 460, shown in FIG. 17, and the packet transmissionunit may include a delivery header insertion unit 470, a protocolencapsulation unit 480, and an internet frontend 490.

Referring to FIGS. 16 and 17, the transmission device 400 sets up a timewindow in operation S500, and converts PSI/SI or audio/video/subtitlemdat into a delivery format according to the set up time window inoperation S510.

For example, the mdat loader (PSI/SI) 425 in the transmission device 400loads the PSI/SI information included in the mdat(PSI/SI) in the fileformat 100, and delivers it to the scheduler 460, and also, the mdatloader(A/V/Sub.) 430 loads actual contents data included each of anmdat(audio), an mdat(video), and an mdat(subtitle) and then, delivers itto the scheduler 460.

The scheduler 460 may cut the PSI/SI information inputted from the mdatloader(PSI/SI) 425 or the audio, video, and subtitle data inputted fromthe mdat loader(A/V/Sub.) 430 according to the set up time window, andthen, may include the cut each data in the delivery format 200 in orderfor sequential output.

Moreover, in the case of the file format 100 as shown in FIG. 15, sincethe PSI/SI information included in the mdat(PSI/SI) is converted intothe PSI/SI signaling information of the delivery format 200 as it is,and then is transmitted, the transmission device 400 according to thesecond embodiment of the present invention may not include the moondecoder 420, the trak(PSI/SI) extraction unit 421, and the PSI/SIgeneration unit 422 shown in FIG. 14.

Then, the transmission device 400 transmits the contents converted intothe delivery format through a network such as internet in operationS520.

Moreover, the transmission device 400 may transmit correspondingcontents by repeatedly performing operation S500 to S3520 shown in FIG.16 until all mdats constituting contents are transmitted.

FIGS. 18 and 19 are views illustrating a method of converting a deliveryformat into a file format, and that is, a method of converting contentsreceived in a delivery format according to an embodiment of the presentinvention as described with reference to FIG. 11 into the file formataccording to a first embodiment of the present invention as describedwith reference to FIGS. 5 to 8 will be described.

Referring to FIG. 18, when contents are received in the file format 200,a reception device may convert the contents received in the deliveryformat 200 into the file format 100 in order to store the contents.

In this case, the PSI/SI signaling information 210, which is included inthe delivery format 200 and transmitted at each predetermined period,may be converted into the trak(PSI/SI) of the file format 100 and may bestored as described with reference to FIGS. 5 to 8.

Additionally, while the contents received in the delivery format 300 areconverted into the file format 100, the reception device continuouslymonitors the version of the PSI/SI signaling information 210 in order toconfirm whether the version is updated.

When the version of the PSI/SI signaling information 210 is updated, thereception device compares the previous version thereof 210 with theupdated version thereof 210 in order to recognize the changed contentstherebetween, and then, reflects information on the changed contents andthe changed time on the trak(PSI/SI) configured using the PSI/SIsignaling information 210 of the previous version in order to store it.

Moreover, an audio packet stream 221, a video packet stream 222, and asubtitle packet stream 223, which are included in the delivery formatand are sequentially received, may be respectively converted into anmdat(audio), an mdat(video), and an mdat(subtitle), and then may bestored.

For example, each of the packet streams is buffered for a predeterminedtime according to time information and is converted into a correspondingmdat, and also, the packet streams may be identified by the mdat_idfield as described with reference to FIG. 11.

When the version of the PSI/SI signaling information 210 is updated, byreflecting the changed contents and the chanted time of the PSI/SIinformation on the trak(PSI/SI) of the file format 100, information on asection that an mdat included in the file format 100 is used may beincluded in the program composition information.

Moreover, the above time information (for example, time information forbuffering the packet streams and converting them into mdats or timeinformation for reflecting a changed time of the PSI/SI information) maybe managed according to a clock of the reception device, and the clockof the reception device may be synchronized with the transmission deviceof the clock reference value Clock Ref. 231 included in the deliveryformat 200.

As described with reference to FIG. 18, by converting the PSI/SIsignaling information of the delivery format 200 into the trak(PSI/SI)and storing it on the basis of the compatibility of PSI/SI information,contents received in the delivery format 200 may be easily convertedinto the file format 100.

FIG. 19 is a flowchart illustrating a method of converting a deliveryformat into a file format according to an embodiment of the presentinvention. FIG. 20 is a block diagram illustrating a configuration of acontents receiving device according to a first embodiment of the presentinvention. Hereinafter, the conversion method shown in FIG. 19 will bedescribed in more detail in linkage with the block diagram shown in FIG.20.

First, when the reception device shown in FIG. 20 is described briefly,the reception device 700 may include a Delivery format decoder, 710, aPSI/SI extraction unit 720, a Version/diff. monitoring unit 721, atrak(PSI/SI) generation unit 722, an mdat butter 730, a PCR extractionunit 740, a system clock 750, a moov generation unit 760, a File formatwriter 770, and a contents DB 780.

Moreover, the contents receiving device according to an embodiment ofthe present invention may include a format conversion unit forconverting contents received in a delivery format into a file format anda contents storage unit for storing the contents having the convertedfile format.

In this case, the format conversion unit of the contents receivingdevice according to an embodiment of the present invention may include adelivery format decoder 710, a PSI/SI extraction unit 720, aVersion/diff. monitoring unit 721, a trak(PSI/SI) generation unit 722,an mdat buffer 730, a moov generation unit 760, and a file format writer770.

Referring to FIGS. 19 and 20, the reception device 700 extracts thePSI/SI signaling information from the delivery format 200 of thereceived contents in operation S600, and then, converts the extractedPSI/SI signaling information into a trak(PSI/SI) and stores it.

The delivery format decoder 710 of the reception device 700 decodes andfilters the delivery format 200 received through internet, and then,separates the decoded filtered delivery format 200 into PSI/SI signalinginformation 210, an audio packet stream 221, a video packet stream 222,a subtitle packet stream 223, and a clock reference value 231 andoutputs them.

For example, the delivery format decoder 710 may identify that dataincluded in a corresponding packet is which one of the audio packetstream 221, the video packet stream 222, and the subtitle packet stream223, by using the mdat_id included in the delivery format 200.

The PSI/SI extraction unit 720 extracts the PSI/SI informationrepresenting composition information on corresponding contents from thePSI/SI signaling information 210, and also, the trak(PSI/SI) generationunit 722 converts the extracted PSI/SI information into the trak(PSI/SI)of the file format as described with reference to FIGS. 5 to 8, andthen, stores it in the contents DB 780.

Additionally, the reception device 700 sets up a time window, andsynchronizes the transmission device 400 with a clock in operation S620.

For example, when a PCR is included in the received delivery format 200,the PCR extraction unit 740 extracts a clock reference value 231 of thetransmission device 400 from the delivery format 200, and delivers it tothe system clock 750.

The system clock 750 may provide the clock synchronized with thetransmission device 400 by using the extracted clock reference value 231to the trak(PSI/SI) generation unit 722 and the mdat buffer 730, andthus, may manage the playback time of the contents received from thetransmission device 400.

Then, the reception device 700 confirms whether the version of thePSI/SI signaling information 210 received in the delivery format 200 ischanged in operation S630.

If the version of the PSI/SI signaling information 210 is changed, thereception device 700 identifies a changed field among the PSI/SIsignaling information 210, and obtains time information from the clockin operation S640.

For example, the Version/diff. monitoring unit 721 may monitor theversion of the PSI/SI information inputted from the PSI/SI extractionunit 720 and by doing so, may identify a difference between the PSI/SIinformation inputted when the version is changed and the PSI/SIinformation of the previous version in order to extract the changedcontents from the PSI/SI information.

In this case, the trak(PSI/SI) generation unit 722 may reflect thechanged contents the Version/diff. monitoring unit 721 extracts on thetrak(PSI/SI) stored in operation S610 in order to update it.

Additionally, the trak(PSI/SI) generation unit 722 may record theinformation on the version changed time on the trak(PSI/SI).

For example, when the version of the PSI/SI information is changed, thetrak(PSI/SI) generation unit 722 may obtain time informationrepresenting the changed time by using the clock provided from thesystem clock 750, and may update program configuration changeinformation of the trak(PSI/SI) (for example, the start time/durationfield values as described with reference to FIG. 6) by using theobtained time information.

As a more specific example, when the Version/diff. monitoring unit 721determines that the version of the PSI/SI information is changed at the180 msec time (this is time information synchronized with thetransmission device 400 according to the system clock) and the main mdatof an audio type changes from the mdat of ‘id1’ into the mdat of ‘id2’,the trak(PSI/SI) generation unit 722 may set each of the duration fieldvalue for the mdat of ‘id1’ and the start time field value for the mdatof ‘id2’ to ‘180’.

The moov generation unit 760 may configure the moov data of the fileformat 100 in order to include the trak(PSI/SI) inputted from thetrak(PSI/SI) generation unit, and then, may output the moov data to thefile format writer 770.

Then, the reception device 700 converts an audio/video/subtitle packetstream into an mdat of a file format according to the set up timewindow, and stores it in operation S660.

For example, the mdat buffer 730 may buffers the audio packet stream221, the video packet stream 222, and the subtitle packet stream 223,which are separated from the delivery format 200 and then sequentiallyinputted, for each predetermined time, and then, may deliver them to thefile format writer 770.

For this, a plurality of the mdat buffers 730 may be provided in thereception device 700 in order to correspond to each of theaudio/video/subtitle packet streams 221, 222, and 223.

In more detail, the mdat buffer 730 may buffer each of the packetstreams 221, 222, and 223 during the time required for the configurationof the mdat by using the clock provided from the system clock and thetime window set up in operation S620.

Moreover, the file format writer 770 configures an mdat by using thebuffered data inputted from the mdat buffer 730, and generates the fileformat 100 to include the moov data inputted from the moov generationunit 760 and the configured mdat, and then, store them in the contentsDB 410.

Moreover, the reception device 700 may store corresponding contents inthe file format 100 by repeatedly performing operation S600 to operationS660 shown in FIG. 19 until all data constituting contents are stored inthe contents DB 780.

FIGS. 21 and 22 are views illustrating a method of converting a deliveryformat into a file format according to another embodiment of the presentinvention, and that is, a method of converting contents received in adelivery format according to an embodiment of the present invention asdescribed with reference to FIG. 11 into the file format according tothe second embodiment of the present invention as described withreference to FIGS. 9 to 10 will be described.

Referring to FIG. 21, the reception device PSI/SI signaling information210, an audio packet stream 221, a video packet stream 222, and asubtitle packet stream 223, which are included in the delivery format200 and are sequentially received, may be respectively converted into anmdat(PSI/SI) 125, an mdat(audio) 121, an mdat(video) 122, and anmdat(subtitle) 123, and then may be stored.

For example, each of the packet streams 210, 221, 222, and 223 isbuffered for a predetermined time and is converted into a correspondingmdat, and also, the packet streams may be identified by the mdat_idfield as described with reference to FIG. 11.

In this case, since the mdat(PSI/SI) 125 of the file format 100 includesthe PSI/SI information where all changed contents are reflected, thereception device buffers the sequentially received PSI/SI signalinginformation 210 as it is for a predetermined time, thereby constitutingthe mdat(PSI/SI) 125.

That is, a conversion method according to further another embodiment ofthe present invention may not include version monitoring and changedcontents extraction processes as described with reference to FIGS. 18 to20.

Moreover, the time information for buffering the packet streams andconverting them into mdats may be managed by the clock of the receptiondevice. The clock of the reception device may be synchronized with thetransmission device of the clock reference value Clock Ref. 231 includedin the delivery format 200.

FIG. 22 is a flowchart illustrating a method of converting a deliveryformat into a file format according to further another embodiment of thepresent invention. FIG. 23 is a block diagram illustrating aconfiguration of a contents receiving device according to a secondembodiment of the present invention. Hereinafter, the conversion methodof FIG. 22 will be described in more detail in linkage with the blockdiagram shown in FIG. 23. Moreover, detailed description for the samecomponents described with reference to FIG. 20 in the configuration ofthe reception device 700 shown in FIG. 23 will be omitted hereinafter.

Moreover, the format conversion unit of the contents receiving deviceaccording to further another embodiment of the present invention mayinclude a delivery format decoder 710, an mdat buffer(PSI/SI) 725, anmdat buffer (A/V/sub.) 730, and a file format writer 770 shown in FIG.23.

Referring to FIGS. 22 and 23, the reception device 700 extracts thePSI/SI information from the delivery format 200 of the received contentsin operation S800.

For example, the mdat buffer(PSI/SI) 725 equipped in the receptiondevice 700 may buffer the PSI/SI signaling information 210, which isseparated from the delivery format 200 and sequentially inputted, for apredetermined time, and then, may deliver it to the file format writer770.

Moreover, in the case of the file format 100 as shown in FIG. 21, sincethe PSI/SI signaling information 210 is buffered for a predeterminedtime as it is in order to constitute the mdat(PSI/SI), the receptiondevice 700 according to the second embodiment of the present inventionmay not include the version/diff. monitoring unit 721 as shown in FIG.20.

The reception device 700 sets up a time window and synchronizes thetransmission 400 with the clock in operation S810.

For example, the system clock 750 may provide the clock synchronizedwith the transmission device 400 to the mdat buffer(PSI/SI) 725 and themdat buffer(A/V/Sub.) 730 by using the clock reference value 231extracted from the delivery format 200, and thus, may manage theplayback time of the contents received from the transmission device 400.

Then, the reception device 700 converts the PSI/SI oraudio/video/subtitle packet stream into an mdat of a file formataccording to a set up time window and stores it in operation S820.

For example, the mdat buffer(A/V/Sub.) 730 may buffer an audio packetstream 221, a video packet stream 222, and a subtitle packet stream 223,which are separated from the delivery format 200 and are sequentiallyinputted, for a predetermined time, and then, may deliver it to the fileformat writer 770.

The file format writer 770 may constitute the mdat(PSI/SI) 125 by usingthe buffered data inputted from the mdat buffer(PSI/SI)(725), and alsomay constitute an mdat(audio) 121, an mdat(video) 122, and anmdat(subtitle) 123 by using the buffered data inputted from the mdatbuffer(A/V/Sub.) 730 in order to generate the file format 100.

Moreover, the reception device 700 may store corresponding contents inthe file format 100 by repeatedly performing operation S800 to S820shown in FIG. 22 until all data constituting contents are stored in thecontents DB 780.

The internet based contents receiving and processing methods asdescribed with reference to FIGS. 1 to 23 may be performed by an IPTVreceiver according to an embodiment of the present invention.

For this, the IPTV receiver may receive contents in a delivery formatfrom a transmission side (for example, a service provider such as abroadcasting station), and the delivery format of the contents may havethe same configuration as described with reference to FIG. 1.

Additionally, the IPTV receiver may convert the contents of the deliveryformat into a file format, and then may store it in a storage mediumtherein, and also, the file format of the contents may have the sameconfiguration as described with reference to FIGS. 4 to 10.

Moreover, the IPTV receiver may convert the contents of the deliveryformat into a file format through the conversion method as describedwith reference to FIGS. 18 to 23.

Hereinafter, referring to FIGS. 24 to 25, the configuration of an IPTVreceiver according to an embodiment of the present invention will bedescribed in more detail with reference to FIGS. 24 and 25.

FIG. 24 is a block diagram illustrating a configuration of an IPTVreceiver according to an embodiment of the present invention.

The IPTV receiver according to an embodiment of the present inventionmay include an additional tuner in order to receive terrestrial wavebroadcast, cable broadcast, and satellite broadcast. However, in thepresent invention, for convenience of description, a configuration forreceiving an IPTV service provided through an IP network will be mainlydescribed.

Additionally, an ITF represents an Open IPTV Terminal Function, and alsorefers to a receiver including a function module necessary forsupporting IPTV service.

The IPTV receiver may include a Network Interface 901, a TCP/IP Manager902, a Service Delivery Manager 904, a PVR Manager 905, a Demux 908, aData Decoder 907, an Audio/Video Decoder 912, an A/V Display & OSDModule 915, Application Managers 913 and 914, a SI & Metadata DB 911, aService Discovery Manager 909, a Service Control Manager 903, a MetadataManager 910, and a Content DB 906.

Referring to FIG. 24, the network interface 901 receives packets from anetwork and transmits packets to the network. That is, the networkinterface 901 receives service and contents from a service providerthrough a network.

The TCP/IP manager 902 is involved in delivering the packet from asource to a destination, with respect to packets received by the IPTVreceiver and packets transmitted from the IPTV receiver. Furthermore,the TCP/IP manager 902 classifies the received packets in correspondenceto a proper protocol, and then, outputs the packets classified into theService Delivery Manager 904, the Service Discovery Manager 909, theService Control Manager 903, and the Metadata Manager 910.

The service delivery manager 904 is responsible for controlling thereceived service data. For example, when realtime streaming data arecontrolled, RTP/RTCP may be used.

When the realtime streaming data are transmitted using RTP, the servicedelivery manager 904 may parse the received data packet according toRTP, and then, may transmit it to the Demux 908 or may store it in thecontents DB 906 according to a control of the service manager 914.Additionally, the service delivery manager 904 feeds the networkreception information to a service providing server through RTCP.

The Demux 908 demultiplexes the received packets into audio, video,Program Specific Information (PSI) data, and then, respectivelytransmits them to the Audio/Video Decoder 912 and the Data Decoder 907.

The Data Decoder 907 decodes service information such as ProgramSpecific Information (PSI), for example. That is, the data decoder 907receives and decodes a PSI section, a Program and Service InformationProtocol (PSIP) section, or a DVB-Service Information (SI) section,which are demultiplexed in the Demux 908.

Additionally, the data decoder 907 decodes the received sections andcreates a database relating to service information, and the databaserelating to service information is stored in the

The Audio/Video Decoder 912 decodes the video data and audio datareceived from the Demux 908. The video data and audio data decoded bythe Audio/Video Decoder 912 are provided to a user through the displayunit 915.

The application manager manages the overall state of the IPTV receiver,provides a user interface, and manages another manager. For this, theapplication manager includes a User Interface Manager 913 and a servicemanager 914.

The Graphic User Interface (GUI) for user through an On Screen Display(OSD), and performs an operation of a receiver according to a key inputfrom a user. For example, when a key input on channel selection isreceived from a user, the key input signal is transmitted to the servicemanager 914.

The service manager 914 controls a manager related to service such asthe Service Delivery Manager 904, the Service Discovery Manager 909, theService Control Manager 903, and the Metadata Manager 910.

Additionally, the service manager 914 creates a Channel Map and selectsa channel by using the channel map according to a key input receivedfrom the user interface manager 913. Then, the service manager 914receives service information on a channel from the data decoder 907, andsets an audio/video Packet Identifier (PID) of the selected channel inthe Demux 908.

The Service Discovery Manager 909 provides information necessary forselecting a service provider that provides service. When a signal onchannel selection is received from the service manager 914, the servicediscovery manager 909 searches for service by using the information.

The service control manager 903 is responsible for service selection andcontrol. For example, when a user selects a Live Broadcasting servicesimilar to existing broadcasting type, the service control manager 903uses IGMP or RTSP, and when a user selects a service such as Video OnDemand (VOD), the service control manager 903 uses RTSP in order toselect and control the service.

The RTSP may provide a trick mode for realtime streaming. Additionally,the service control manager 903 initializes a session through an IMCgateway by using IP Multimedia Subsystem (IMS) and Session InitiationProtocol (IMS). The protocols are one embodiment, and other protocolsmay be used according to an implementation example.

The metadata manager 910 manages service related metadata and stores themetadata in the SI&Metadata DB 911.

The SI & Metadata DB 911 may store the service information decoded bythe Data Decoder 907, the metadata that the metadata manager 910manages, and the information necessary for selecting a service providerthat the service discovery manager 909 provides. Additionally, the SI &Metadata DB 911 may store setup data for system.

The SI & Metadata DB 911 and the NonVolatile RAM (NVRAM) or flashmemory, or may be implemented using two areas that are logicallyseparated on the same storage area.

The PVR Manager 905 collects metadata on recorded contents and createssupplement information provided to a user through thumbnail image orindex, as a module for recording live streaming contents and playingthem

Functions of a control unit in the IPTV receiver according to anembodiment of the present invention are separated and implemented by aplurality of modules such as the TCP/IP Manager 902, the ServiceDelivery Manager 904, the PVR Manager 905, the Application Managers 913and 914, the Service Discovery Manager 909, the Service Control Manager903, and the Metadata Manager 910, shown in FIG. 24.

For example, the TCP/IP Manager 902 filters SD&S information by usingthe above-mentioned target package information in order to control theNetwork Interface 902 to request only the payload or segmentcorresponding to a specific package (for example, a package that an IPTVreceiver subscribes) to a server and receive it.

Or, the TCP/IP Manager 902 filters SD&S information, which is receivedin a multicast way, by using the target package information in order toallow the data decoder 907 to parse and process only the payload orsegment corresponding to a specific package.

FIG. 25 is a block diagram illustrating a configuration of an IPTVreceiver according to an embodiment of the present invention, and thatis, a configuration of an IPTV receiver is represented with functionalblocks. The solid arrow shown in FIG. 25 corresponds to a data path, andthe dashed arrow corresponds to a control signal path.

A Cable modem, a DSL modem, etc(1001) demodulates a signal transmittedthrough a physical medium and restores the digital signal, as aninterface that allows an ITF to be connected to an IP Network in aphysical level.

An Ethernet NIC 1002 restores the signal, which is received through thephysical interface, to IP data, and an IP Network Stack 1007 processeseach layer according to an IP

Protocol stack.

Additionally, an XML Parser 1009 parses MXL Document in the received IPdata, and a File Handler 1008 processes data, which are transmitted in afile format through FLUTE, among the received IP data.

A SI Handler 1011 may process a portion corresponding to the IPTVservice information among the received data of the file format and thenmay store it in a storage 1012, and the EPG Handler 1010 may process aportion corresponding to the IPTV EPG information among the receiveddata of the file format and then may store it in the storage 1012.

The Storage 1012 stores various data such as the SI and the EPG.

An SI Decoder 1013 receives SI data from the storage 1012 and analyzesthem in order to obtain channel map information, and an EPG Decoder 1014analyzes the EPG data stored in the Storage 1012 in order to restoreinformation necessary for an EPG configuration.

An ITF Operation Controller 1015 is a main controller for controlling anoperation of an ITF such as Channel change or EPGP display.

A Channel Service Manager 1016 may perform an operation such as channelchange according to a user input, and an Application Manager 1017 mayperform Application service such as EPG Display according to a userinput.

An MPEG-2 Demultiplexer 1003 may extract MPEG-2 Transport Stream datafrom the received IP Datagram, and may deliver them to a correspondingmodule according to packet identification information (PID).

Additionally, an MPEG-2 PSI/PSIP Parser 1004 may extract PSI/PSIP data,which includes packet identification information (PID) on A/V data oraccess information on a program element, from the MPEG-2 TransportStream, and then, may parse them.

Moreover, an A/V Decoder 1005 may decode the inputted Audio and Videodata and then, may deliver them to a display module 1006. The Displaymodule 1006 may output the decoded A/V data or application.

The contents transmitting/receiving method according to the presentinvention can also be embodied as computer readable codes on a computerreadable recording medium. The computer readable recording medium is anydata storage device that can store data which can be thereafter read bya computer system. Examples of the computer readable recording mediuminclude read-only memory (ROM), random-access memory (RAM), CD-ROMs,magnetic tapes, floppy disks, and optical data storage devices, andfurther includes carrier waves (such as data transmission through theInternet.

The computer readable recording medium can also be distributed overnetwork coupled computer systems so that the computer readable code isstored and executed in a distributed fashion. (Also, functionalprograms, codes, and code segments for accomplishing the presentinvention can be easily construed by programmers skilled in the art towhich the present invention pertains.)

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the present invention as defined by the following claims.

1-20. (canceled)
 21. A method of transmitting contents through internet,the method comprising: converting contents stored in a file format intoa delivery format; and transmitting the contents converted into thedelivery format by using IP packets, wherein the delivery formatincludes a packet stream including the IP packets for transmitting oneor more media contents data entities and program compositioninformation, and the IP packets include time information forsynchronization.
 22. The method of claim 21, wherein the timeinformation is a clock reference value for clock synchronization betweentransmitters/receivers.
 23. The method of claim 22, wherein the clockreference value is designated by a PCR_base field and a PCR_extensionfield included in the delivery format.
 24. The method of claim 21,wherein the delivery format comprises length information forrepresenting the size of data included in the IP packet.
 25. The methodof claim 21, wherein the file format includes a contents container for aprogram, the contents container one or more media contents data entitiesbelonging to the program, and program composition information for theprogram, the one or more media contents data entities corresponds tovideo data, audio data or subtitle data.
 26. The method of claim 25,wherein the program composition information includes one or moreidentifiers corresponding to the one or more media contents dataentities belonging to the program, respectively, and each of the one ormore identifiers identifies corresponding media contents data entity.27. The method of claim 25, wherein each of the one or more mediacontents data entities is cut according to a time window, and then, acut media contents data entity is included in the delivery format, andthe delivery format is included in payload of the transmitted IP packet.28. A method of receiving contents through interne, the methodcomprising: converting contents received in a delivery format into afile format; and storing the contents converted into the file format,wherein the delivery format includes a packet stream including the IPpackets for transmitting one or more media contents data entities andprogram composition information, and the IP packets include timeinformation for synchronization.
 29. The method of claim 28, wherein thetime information is a clock reference value for clock synchronizationbetween transmitters/receivers.
 30. The method of claim 29, wherein theconverting of the contents is performed by using a system clocksynchronized with a transmitter through the clock reference value. 31.The method of claim 28, wherein the file format includes a contentscontainer for a program, the contents container one or more mediacontents data entities belonging to the program, and program compositioninformation for the program, the one or more media contents dataentities corresponds to video data, audio data or subtitle data.
 32. Themethod of claim 31, wherein the program composition information includesone or more identifiers corresponding to the one or more media contentsdata entities belonging to the program, respectively, and each of theone or more identifiers identifies corresponding media contents dataentity.
 33. A device of transmitting contents through internet, themethod comprising: a format conversion unit for converting contentsstored in a file format into a delivery format; and a packettransmission unit for transmitting the contents converted into thedelivery format by using IP packets, wherein the delivery formatincludes a packet stream including the IP packets for transmitting oneor more media contents data entities and program compositioninformation, and the IP packets include time information forsynchronization.
 34. The device of claim 33, wherein the delivery formatcomprises length information for representing the size of data includedin the IP packet.
 35. The device of claim 33, wherein the file formatincludes a contents container for a program, the contents container oneor more media contents data entities belonging to the program, andprogram composition information for the program, the one or more mediacontents data entities corresponds to video data, audio data or subtitledata.
 36. The device of claim 33, wherein each of the one or more mediacontents data entities is cut according to a time window, and then, acut media contents data entity is included in the delivery format, andthe delivery format is included in payload of the transmitted IP packet.37. A device of receiving contents through internet, the methodcomprising: a format conversion unit for converting contents received ina delivery format into a file format; and a contents storing unit forstoring the contents converted into the file format, wherein thedelivery format includes a packet stream including the IP packets fortransmitting one or more media contents data entities and programcomposition information, and the IP packets include time information forsynchronization.
 38. The device of claim 37, wherein the formatconversion unit performs file conversion by using a system clocksynchronized with a transmitter through the time information.
 39. Thedevice of claim 37, wherein the file format includes a contentscontainer for a program, the contents container one or more mediacontents data entities belonging to the program, and program compositioninformation for the program, the one or more media contents dataentities corresponds to video data, audio data or subtitle data.
 40. Thedevice of claim 39, wherein the program composition information includesone or more identifiers corresponding to the one or more media contentsdata entities belonging to the program, respectively, each of the one ormore identifiers identifies corresponding media contents data entity,and the format conversion unit converts IP packets into the one or moremedia contents data entities by using the one or more identifiers.